terryowens

Hi all. I am in a bad way trying to pass my 1989 Honda Accord LX-i 's emissions here in Georgia. Honda-Tech has been a great resource for learning more about emissions and I have exhausted myself on the search engine. I am posting my account for any who are willing to share their expertise.

My Accord runs great. It has 255,000 miles on it with most of the service and repair done at the Honda dealership. It has run a long time because I take care of it.

Emissions tests here in Georgia have NEVER been a problem for this car in the past. My old emissions reports from 2003-2005 are as follows:

HC (hydrocarbons) -- a range of 18 - 30 w/ allowances in the 180s.
CO (carbon monoxide) - a range of .02 - .07 w/ allowances around 1.10
NOx (Nitrous gases?) - a range of 372 - 633 w/ allowances between 1300-1400

*** I noticed the NOx numbers have steadily risen from 372 in 2003 to 633 in 2005. I'm still way under the allowance for NOx, but just wanted to state that observation. All other fluctuations do not appear to be directly related to "aging".


I have had my car tested 4 times already in 2006. I cannot pass the CO test at 15mph for 50 seconds. Yes I drive my car a good 30 min on the Interstate before ALL the tests. My first test yielded these results:

HC --> 89 - 105 (two numbers for 25/25 and 50/15 tests)
CO --> 1.61 - 1.86 <----------FAILED
NOx --> 784 - 863


Needless to say I was stunned. Thanks to Honda Tech users, I was able to diagnose some simple fixes. I replaced:

02 oxygen sensors (Honda OEM)
Spark Plugs
Air Filter

My retests brought my HydroCarbons down around the 60s. Still nowhere near the normal levels of past years (18 - 30). Since HC is unburned fuel, the CO also came down to 1.2 - 1.3. It's clear the new oxygen sensors helped and I did find a questionable spark plug when I replaced those, but I am still about .15 over the limit on the 50/15 dyno test. (Still well over what is normal .02 - .06)

**** The "bad" spark plug had no discoloration. The ground electrode looked "bent" down so close to the insulator pin that the gap was almost as thin as a sheet of paper.


So after that failure I decided to hand my car over to my Honda mechanic friend. He has worked at a dealership for 10+ years and has done a lot of the service on my car. This is what he did:

Replaced distributor (cap?) and rotor
Checked continuity of plug wires
Took off the manifold head and blew out all the carbon buildup
Inspected the fuel injectors and said he could find no problems or leaks
Oil and filter change for convenience.

**** He also retarded the timing of my distributor claiming he has always had success passing cars with this technique. I wanted to doubt him as I thought I read some differing opinions here on Honda Tech. High CO is due to a rich mixture caused by too much fuel or not enough air intake to burn the fuel. I didn't question him but maybe I should have.


So I took my car in for the latest retest and it still fails the CO @ 50/15 with a 1.20 reading -- 1.05 allowable. I'm still .15 too high. Also it appears as if retarding the timing of the distributor may have had an INVERSE effect on the HC and CO 25/25 test. Those numbers actually went back UP to 88(HC) and 1.13(CO) from previous readings around 60 and .5-.6 for the 25/25. I'm going to set the timing back right.


So now I'm in the Honda Service manual thinking my problem is either:
Catalytic Converter
Vacuum Leaks
Air Intake System
or
Evaporative Emission Control System

Where should I start? I don't think it's the cat because my NOx isn't that much of a problem. Like I said the NOx numbers have risen over the years but are still waaay under the allowance. What else can I do to increase the air in my fuel mixture or decrease the richness of the mixture?


Modified by terryowens at 11:58 PM 5/8/2006


Modified by terryowens at 12:03 AM 5/9/2006


Modified by terryowens at 12:03 AM 5/9/2006


Modified by terryowens at 12:04 AM 5/9/2006

S CARTER

I wasn't quite clear on if your tech did or didn't replace your dis cap. If he didn't i would start with that.

Maybe a pcv valve.

And i no this last one sounds a Little sketch, but i heard it works and for the price why not?

http://xcelplus.com/xp_product...s.htm

terryowens

Thanks for your input S Carter. Yes my Honda mechanic friend replaced the distributor cap. I put that in parenthesis because I couldn't remember if that was the correct term. I think it is.

I'm going to get a Vacuum Pump/Gauge and start checking some of these vacuums....

Evaportaive Emissions Control
Idle Control System


I found a good post in the archives on idle/emissions. My car has definitely had idleing issues in the past and I'm not sure what kind of adjustments the service techs have made over the years. Does anyone know if I can get more air into the fuel mixture by adjusting the Idle Adjustment Screw counterclockwise on my 1989 PGM-FI? That would improve my CO emissions if the combustion process had more air to burn the fuel right?

terryowens

I'm really hoping it's not my cat. My mech friend claims he rarely sees cats go bad but maybe he is just trying to make me feel better about dropping $500!

Nothing I've found in the archives suggests that a high CO reading = bad cat. Reading through the service manual, it sounds more likely I have an ICS valve problem.

My car is idleing fine right now, but maybe that's because it's been tweaked too rich?

blueshark

I read your readings and found it interesting that you failed CO. but your NOx readings were still high. Richer running cars normally have lower NOx levels due to lower combustion chamber temps. Catalysts go bad all the time! Look for an inexpensive Cat. and take it to a different check point. Those machines are falable!

terryowens

Thanks for your input blueshark.

So you think my NOx levels around 700 out of an allowable 1300-1400 are high? I am not running too rich then, iyo? Interesting. Like I described in my original post, the NOx levels in earlier emissions reports from previoius years were:

50/15 test
2003 -> 372
2004 -> 408
2005 -> 633

I am on my 5th test for 2006.
The results of the NOx 50/15 test have fluctuated randomly!
My lowest reading was 400 while the highest was over 800 after 5 different tests.

When compared alongside the other 25/25 tests from previous years, I can generalize the NOx numbers have steadily increased, however I actually recorded an NOx reading as low as my 2003 results on one of the most recent tests. This is almost maddening!

My HC and CO readings are <U>definitely</U> higher across the board in 2006 compared to previous years. Although my HC passes the tests, they are twice as much when compared to any of the previous emissions reports from 2003-2005.

My real problem is high CO Carbon Monoxide. I used to have readings of .02-.06 %. Now I am well over 1%. I guess I am clinging on to thinking there is something wrong with my idle/mixture. I feel that if it was the catalytic converter, I would be failing more than 1 out of the possible 6 categories.


Modified by terryowens at 3:50 AM 5/10/2006


Modified by terryowens at 3:51 AM 5/10/2006

the jdmchop

in CT we have a $660 waiver fee, if ya got recipts saying you spent more than 660 tring to fix the car they give you a waiver!

make sure the inspector uses a fan to cool off the car that helps big time with nox

terryowens

Thanks for the input.

I am failing CO though. Not NOx. My NOx is relatively normal, imo. I can probably get a waiver here in GA but I may want to sell this car soon and I need it to pass emissions to get what I want for it.

Thanks everyone for your thoughts so far.

terryowens

Alirght, time for an update.

Looking at the air intake system and throttle, I checked my PCV valve. When I pulled off the hose that goes from the top of the valve to the throttle body, it rained down soot and carbon all over the place! The PCV valve was covered in gummy soot/oil.

AH HA! I said.

So the next bright idea I had was to remove the PCV valve, clean it, and see if it would still work. Well my car is 17 years old and when I tried to pull the PCV out, it obviously broke inside the other hose. Great. I literally crushed the valve with a screwdriver to remove it, along with destroying the top of the S shaped tube that connects the valve to the engine breather box chamber.

UGH.

Basically I had to replace the breather chamber, tube joint, tubes, AND the PCV valve. The tubes, hoses, and grommits had all basically "fused" and molded together under the extreme temperatures from the past 17 years. What I thought was going to be a quick replacement ended up being quite extensive.

However, I feel that since the PCV valve/tubes were blocked, this prevented blow-by gas and vapors from the breathing chamber from recirculating back to the intake manifold to complete their combustion process. This sounds encouraging for my Carbon Monoxide problem, however it could also signal that my catalytic converter has been subjected to "rich" combustion exhaust for some time and may have caused it to wear down. Coupled with the fact I found a misfiring spark plug that I replaced, my cat could be next on the docket for replacement.

I will be getting a new emissions test soon after I check some more vacuum hoses/sensors.

Chiovnidca

Have you checked that the mechanical distributor advance is free? Sometime they get sticky.

Is the vacuum advance working properly. Does it hold vacuum?

terryowens

Hmmm. I'm not sure I even know what the mechanical distributor advance even is.

Thanks for your help Chiovnidca. I recognize your name from past research on this board. I know at one point you posted something that helped me out tremendously with another issue. You must know older Hondas!

I'm glad you're here.


I am trying to check the vacuum on the throttle body right now using the purge port from the charcoal canister. Much like the PCV issue, the red fabric lined hose has hardened and melted to the port. I disconnected it from the other side and blew into it. Low and behold the red fabric hose has a crack on the underside! HA! And I haven't even plugged my gauge up yet!

I'll get a new one Monday, but for now I'm just going to cut it where the break is and try to still use it to finish my vacuum and Evaporative Emissions testing on the charcoal canister.


I have a 1987 OEM service manual for my 1989 Accord. I can't seem to find anything on the "vacuum tank" component directly in front of the charcoal can. It's in the vacuum hose diagram under the hood. Is that something I should be doing more research on?

terryowens

OK so the vacuum advance unit is on the distributor. I'll look into it, C. Thanks for the tip. I did replace the distributor cap and rotor thinking this may have been causing one of my spark plugs to misfire.

terryowens

Chiovnidca, I checked the vacuum advance diaphragms on my distributor. Neither of the two will hold a vacuum when I pump the port with the hand pump. Service manual says the diaphragms should hold a vacuum over 20 in so it can turn the stator.


What does this mean? (Other than I need to replace the v.a.d. on the distributor)


I'm also curious as to what the "vacuum tank" in front of the charcoal canister is. I gotta get my hands on a bona fide OEM 1989 Accord service manual.

terryowens

OK I found a nice description of the vacuum advance in another post by ludegetsmwet

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">As you accelerate from idle, the speed of your engine increases. This increase in engine speed means that the pistons are now traveling up and down much faster. Because of this, the spark plugs will have to fire even sooner if the mixture is to be completely ignited as the piston passes TDC. To accomplish this, the system incorporates a means to advance the timing of the spark as the engine speed increases. The mechanical distributor has two means of advancing the ignition timing. One is the centrifugal advance and is actuated by weights in the distributor. The other is a vacuum advance and is controlled in that large circular "can" on the side of the distributor. Fully eletronic systems use the Enginc Control Unit to control the trigger signal to the coil. The computer can provide for much more accurate spark control than mechanical units. In addition, some Honda distributors have a vacuum retard mechansm which is contained in the same housing on the side of the distributor as the vacuum advance. Models having two hoses going to the distributor vacuum housing have both vacuum advance and retard. The function of this mechanism is to regulate the timing of the ignitnion spark under certain engine conditions. This causes more complete burning of the air/fuel mixture in the cylinder and consequently lowers exhasut emissions. </TD></TR></TABLE>


I'm starting to believe the big picture now.

My vacuum advance diaphragm is SHOT, hence a vacuum leak.
It likely contributed to a spark plug malfunction.
Both of these likely contributed to a rich air/fuel mixture.
This rich mixture likely contributed in clogging the PCV valve.


I'm not sure about how to check the centrifugal/mechanical advance so I think I'm gonna let my friend do an overhaul on these distributor problems before I do anything else like replace the cat. All the emissions control systems are up to snuff now. I still need a 1989 OEM service manual to really check the idle control system, but my idle really is perfect right now.

All efforts are concentrated on removing this vacuum leak that is causing subversive ignition problems. I just hope I'm able to correct everything before my catalytic is toast. Rich mixtures and misfiring cylinders are not the catalytic converter's best friend from what I can find in the archives.




Modified by terryowens at 11:30 PM 5/13/2006

terryowens

SOB!

I just recieved the vacuum advance control I ordered from Advance Auto Parts and the ports are on the wrong side of the unit. URGH!@! I guess OEM doesn't mean a dern thing to them! My old unit has a blue dot sticker on the top port. The new one has a pink dot sticker and the ports point right at the thermostat housing. Useless.

I see Napa has one pictured as "canadian emissions" with the blue dot that looks JUST LIKE MINE. Man this is pizzing me off. Why does everything have to be such an ordeal these days???

Chiovnidca

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by terryowens &raquo;</TD></TR><TR><TD CLASS="quote">SOB!

I just recieved the vacuum advance control I ordered from Advance Auto Parts and the ports are on the wrong side of the unit. </TD></TR></TABLE>
They used 2 different distributors, TEC and Hitachi. The vac adv isn't interchangable between the two.

hondadude

the fuel injected engines[LXi] used the TEK dist

terryowens

Thanks for keeping me in the loop Chiovnidca and hondadude.

Yes the unit I ordered from Advance Auto Parts was in fact a <u>TEC unit</u>. It even had the TEC logo on it. It looked exactly the same as mine except the hose ports were turned to 12 o'clock where the original unit's are at 5 o'clock. And it had a pink dot sticker on the top port instead of a blue one like my original. I returned it and told the Advance guy the part didn't match. The hose ports were touching the thermostat housing instead of pointing up towards the hose lines.

Looking at some of the online Honda parts stores, I come across two part numbers listed for my vehicle:

30104-PJ0-A03 CONTROL, VACUUM
30104-PJ0-A13 CONTROL, VACUUM


I called my local Honda dealer and had him run my VIN. He says mine is an "A13". Not "A03". According to some of the descriptions I was able to find, the "A03" is for California?? This is so frustrating because none of the web sites have any pictures. I guess I'll order it from Majestic or hondapartsstore. Just have to wait a few more days. ::sigh::

terryowens

Yea!

My vacuum advance control unit (the right one) arrived today from Honda! Install was a snap. Now I'm going to check my centrifugal timing advance and ignition timing with an advanced timing light before I get my latest emissions test.

terryowens

My latest emissions test still fails CO by .15%


Well guys, it looks like the next step is replacing the cat. I think my old broken vacuum advance unit made my car run rich and probably affected the cat just like the clogged PCV valve and the misfiring spark plug that I had to replace.

Ross 2.0

Now that you have that fixed mabye you can blast the car down the road one time and get the converter really hot to clean it out.
I don't know a whole lot about emissions testing but I do own the same car and if I drive it easy for a few days then get on it hard the exhaust stinks for a while. That's it burning off all of the residues that could not be burned before because it wasn't getting hot enough.
Just one more shot to take before dumping money into a converter.